Driving mechanism



p 7, 1937. A. JOHNSON 2,092,375

DRIVING MECHANI SM Filed Dec. 22, 1934 Patented Sept. 7, 1937 UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to tension control, and especially to tension controlled driving connections for apparatus actuated in accordance with the movement of elevator cars.

This application is a continuation in part of my prior application, filed April 9, 1934, Serial No. 719,727, for Driving mechanism.

It is frequently desirable in an elevator system to have a mechanical element actuated in accordance with the vertical movement of the elevator car in the hatchway. Such a mechanical element or device may be made to operate various mechanism associated with, or incorporated in, the elevator system to accomplish a variety of functions.

The principal object of the invention is to provide a differential drive for a single tape extending from the car to a tape reel in driving relation with a floor controller, whereby the reel is driven by motion derived from the driving means of the elevator, and to construct the driving mechanism sothat a torque motor, differentially connected with the tape reel, drives the reel jointly with a rotatable member of the driving means, and exerts a certain fixed torque upon the reel at all times and controls the torque factor of the power communicated to the reel by the movement of the said rotatable member of the driving means for the elevator car, so that power is communicated in proportion to the Work required for driving the reel or pulling device for the tape or lineal element.

Other objects will become apparent from the specification taken in consideration with the accompanying drawing and the subjoined claims.

Referring to the drawing in which like reference characters denote similar parts in all the figures:

Figure 1 is a view illustrating my invention as applied to driving a reel.

Figure 2 is a view illustrating the arrangement of the gearing shown in Figure 1. The present embodiment of the invention includes the following elements which have counterparts from the standpoint of functions performed in any modification: A rotatable member, such as a shaft, that constitutes a movable part of a driven mechanism, as an elevator machine; connections thereto capable of positively advancing an element having lineal continuity, as for example a flexible member anchored to a movable body such as an elevator car; a rotatable device, such as a reel or drum; a differential or differential motion mechanism with an input element connected to the rotatable member, and an output element connected to the reel and a differentially connected electric torque motor connected to or forming a second input element, to exert a pull.

Referring to Figure 1 of the drawing, the elevator car designated 24 is raised and lowered in the hatchway by means of hoisting ropes passing over a sheave 4 driven by a motor 3. A train of differential back gearing is connected to the cable sheave 4, as by the extension shaft 5. A reel II is connected to the rotatable member 5, through the intermediary of said differential gearing, as by the sprockets l8 and I9 and the belt 20. A shaft l6 connects the reel II in driving relation with the controller 0. A torque controlled brake member I! is operatively connected to the shaft l6, as at 22, and to the freely rotatable sprocket l9 thereon, as at 2 I. A flexible cable or tape 10, at the one end is secured to the reel I and is wound thereon a number of times equal to the travel of the car. The other end of the tape I0, is associated with the car 24 and the slack tape switch 25. The gear train of the differential, in the present instance, consists of the idler gears l, radially disposed about a central gear l5, and in turn mesh with a rotatable internal gear 9, see Figure 2. The rotatable member 5 is connected in driving relation with the rotatable gears l, by a spider 6. The sprocket I8 is secured to the rotatable spur gear I5, A gear I 4, is carried by and rotatable with the gear 9. A torque motor 8, has a pinion l2, meshing with the gear l4.

A suitable source of electric current supply is applied to the torque motor 8, to enable the motor to rotate the gear l2, and intermediate mechanism to drive the reel H and thereby keep the tape [0 under constant tension, when the car is at standstill as well as while in motion, in either direction.

Preferably, the arrangement of the equipment, between the rotatable member 5 and the shaft I6, is such that the ratios of the differential gearing and the other motion mechanism, are of such proportions as to subject the torque motor 8, on the one hand, to a slow reverse movement when the reel l l is taking in tape and the car is moving upward, and, on the other hand, to a slow forward or driving movement, to wind up the tape ID that is now being unwound at too fast a rate by the movement of the rotatable member 5, when the car is moving downwards. This arrangement effects movement of the reel by motion derived from the movement of the driving means of the elevator car, and the .reel and the device 0 are driven in accordance with the movement of the car, without subjecting the tape to the driving effort.

The action of the reel brake, when the tape parts or becomes abnormally slack, prevents the tape from unwinding off the reel H due to the weight of such tape as depends therefrom. The motor 8, when energized, by rotation of the sprocket 19, effects contraction ofthe member if and thereby release of the brake andliolds' the tape l0 taut at all times; I The brake drum 23 is placed so as to be engageable with the member ll when the torque on the shaft It falls below a predetermined value. While I have shown the torque controlled brake member l? in the form of a helical spring, it is to be understood that a band may be used. The applicants copending application, Serial No. 748,976, filed October 19, 1934, describes andclaims a torque controlled brake band suitable for a reel brake.

It is to be understood, of course that this invention is not limited to the type of motion mechanism andequipment illustrated nor to the particular differential described. Such gearing and equipment are to be considered as merely schematic and illustrative of one manner of connecting a torque motor differentially to drive a reel or rotatable device, adapted to handle an element having lineal continuity and positively advanced by connections associated with driven mechanism, so that said torque motor drives said rotatable device jointly with said driven mechanism, controls the torque factor of the power transferred to the reel from the movement of the said driven mechanism and maintains the element connected with the reel and a driven member of driven mechanism under a substantially constant tension, when said driven mechanism is stationary as well as while in motion, in either direction.

As a consequence, it is not intended that this invention is to be limited to the specific equipment illustrated, and I, therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

Having thus described'the invention, what is claimed is:

1. In an elevator system, an arrangement for driving a device having a movable element for actuation in accordance with the movement of an elevator car, including an elevator car; driving means for the car including a rotatable member, a reel in driving relation with said device, a tape connecting said reel and said car, the combination therewith of a driving connection between the rotatable member' and the said reel, including a difierential having an inputelement connected to the rotatable member and an 'out-' put element connected to the reel, an electric torque motor connected to a second input element of the said differential and effective at all times, when energized, for controlling the torque factor of the power transferred from the movement of. the rotatable member. and for applying, through the intermediary'of the differential and the said reel, a substantially constant tensioning force upon said tape while said car is in motion, in either direction, as well as while said car is stationary.

2. In an elevator mechanism, an arrangement for driving a device'having a movable element for actuation in accordance with the movement of an elevator car, including an elevator car, driving means for the elevator car including a rotatable member, a reel in driving relation with the said element.

ferential, said motor effective at all times, when energized, for causing a substantially constant torque to be applied upon said reel to keep said tape under tension as the speed of, the car varies and while said car is stationary.

3. In an elevator system, an arrangement for drivinga device having a movable element for actuation in accordance with the movement of an elevator car, including an elevator car, driving means for the elevator car including a ro- 'tatable member, a reel in driving relation with the movable element of the said device, a flexible member connecting'said reel and said car, the combination therewith of a driving connection between the rotatable member and the said reel and a brake drum, said driving connection including an expansible brake member connected to said reel and arranged for automatic pressure engagement with said brake drum, a train of differential gearing having an output element connected with said brake member and an input element connected with the rotatable member, and an electric torque motor connected to another element of the'gearing, whereby said torque motor, when energized, is enabled to release said brake member from said brake drum and main.- tain said flexible member under continuous tension regardless of the movement of the said ro-' tatable member.

4. An arrangement for tensioning an element having lineal continuity comprising in combination, a rotatable device adapted to propel said element, a driven member governing the forward feed of the element, driving mechanism including a rotatable member, driving means for connecting said driving mechanism and said driven member, and an electric torque motor differentially connected to said rotatable member and hence to the driving mechanism and to the said rotatable device, through the intermediary of connections exclusive of the said driving means, whereby when said rotatable member is driven it will drive said rotatable device through the said connections, the torque motor functioning regardless of the movement of the rotatable member to maintain a continuous tension upon 5. In an arrangement for tensioning an element having lineal continuity, a rotatable device adapted to propel said element, a driven member governing the forward feed of the element, driving mechanism including a rotatable member, driving means for connecting said driving mechanism and said driven member, an electric torque motor, a differential mechanism and connections, embodying means exclusive ofthe said driving means, for interconnecting said rotatable member, said torque motor and said rotatable device, so, that when said rotatable member is driven it will drive said rotatable device, the torque motor functioning regardless of the movement of the rotatable member to maintain a continuous tension upon the said element.

6. A tensioned driving connectioncomprising in combination. a lineal element, a driven member governing the forward feed of said element, driving mechanism for said driven member including a rotatable member and means for connecting said driving mechanism and said driven member, a rotatable device adapted to propel said lineal element, means embodying means exclusive of said first means for driving said rotatable device in conjunction with the movement of the driven member, including an electric torque motor connected, through the intermediary of a differential mechanism, to said rotatable member and hence to the driving mechanism and to the said rotatable device, so that when said rotatable member is driven it will drive said rotatable device, the torque motor functioning regardless of the movement of the rotatable member to maintain a substantially constant tension upon the said lineal element.

7. In a tensioned driving connection, a tape connecting a reel with a driven member governing the forward feed of said tape, driving means for said driven member and means for causing said reel to wind and unwind said tape in accordance with the movement of the said driven member including means for maintaining said tape under continuous tension; the combination therewith of a brake drum and an expansible friction member connecting said last mentioned means and the said reel and arranged for automatic pressure engagement with the brake drum when the tension in the tape falls below a predetermined value.

ALFRED JOHNSON. 

